{"id":"CVE-2026-80807","title":"nilfs2: reject invalid block index in GC ioctl","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: reject invalid block index in GC ioctl\n\nSyzbot reported list corruption caused by a double list_add_tail() call on\nbh->b_assoc_buffers within nilfs_lookup_dirty…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < 898404cdf882d7b54f1132f75570984ca3214796","Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < ba8a8b563a28d358c45c62a306d421434a058648","Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < 3bd064ccc70b85f9a3d53aece29dc8473be5a226","Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < a5e776e2937581d67ec5b9b4d27b0f70d7baa6b1","Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < 68aa9ab6f8f2895713aa6ddf781463ed8ea5ba44","Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < e447f7edb99bd00cec63d6f3049e2e5074946f71","Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < ec6ddf271dfa4c7e3147bc2c8b2bad4315f316a1","Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < fbcfb75c20d71a5b542ad4ac3b79d10b997c8152","Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < a1735eae55448bc79c2da6593455791e886f6ed8","Linux 2.6.30"],"published":"2026-09-04","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:44:00.360Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80807","references":[{"url":"https://git.kernel.org/stable/c/898404cdf882d7b54f1132f75570984ca3214796"},{"url":"https://git.kernel.org/stable/c/ba8a8b563a28d358c45c62a306d421434a058648"},{"url":"https://git.kernel.org/stable/c/3bd064ccc70b85f9a3d53aece29dc8473be5a226"},{"url":"https://git.kernel.org/stable/c/a5e776e2937581d67ec5b9b4d27b0f70d7baa6b1"},{"url":"https://git.kernel.org/stable/c/68aa9ab6f8f2895713aa6ddf781463ed8ea5ba44"},{"url":"https://git.kernel.org/stable/c/e447f7edb99bd00cec63d6f3049e2e5074946f71"},{"url":"https://git.kernel.org/stable/c/ec6ddf271dfa4c7e3147bc2c8b2bad4315f316a1"},{"url":"https://git.kernel.org/stable/c/fbcfb75c20d71a5b542ad4ac3b79d10b997c8152"},{"url":"https://git.kernel.org/stable/c/a1735eae55448bc79c2da6593455791e886f6ed8"}],"tags":["cve.org"],"epss":0.00201,"epssPercentile":0.0926,"ingestedAt":"2026-10-19T09:16:01.525Z","slug":"CVE-2026-80807","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: reject invalid block index in GC ioctl\n\nSyzbot reported list corruption caused by a double list_add_tail() call on\nbh->b_assoc_buffers within nilfs_lookup_dirty_data_buffers().\n\nAnalysis revealed that the root cause was the insertion of a page/folio\nwith a page index of ULONG_MAX into the page cache via the GC ioctl.\nfilemap_get_folios_tag(), called by nilfs_lookup_dirty_data_buffers(),\nrepeatedly detects a dirty folio with a page index of ULONG_MAX due to\nindex wrap-around, leading to duplicate processing of dirty buffers.\n\nAs a preparatory step, the GC ioctl loads the page/folio of the block to\nbe moved during GC and inserts it into the page cache based on information\nin the nilfs_vdesc structure passed as an argument.  Normally, this does\nnot cause issues because the user-space GC library configures the\nnilfs_vdesc structure properly.  However, since there is no range check on\nthe parameters determining the page index, a request with artificially\ncrafted parameters -- such as those generated by Syzbot -- can result in a\npage/folio being inserted with a page index of ULONG_MAX, triggering the\nabove problem.\n\nThis resolves the issue by checking the ranges of 'vd_offset' and\n'vd_vblocknr' in the nilfs_vdesc structure that determine the page index,\nthereby preventing the invalid page/folio insertions.\n\n## Affected\n\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < 898404cdf882d7b54f1132f75570984ca3214796`\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < ba8a8b563a28d358c45c62a306d421434a058648`\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < 3bd064ccc70b85f9a3d53aece29dc8473be5a226`\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < a5e776e2937581d67ec5b9b4d27b0f70d7baa6b1`\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < 68aa9ab6f8f2895713aa6ddf781463ed8ea5ba44`\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < e447f7edb99bd00cec63d6f3049e2e5074946f71`\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < ec6ddf271dfa4c7e3147bc2c8b2bad4315f316a1`\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < fbcfb75c20d71a5b542ad4ac3b79d10b997c8152`\n- `Linux >= 7942b919f7321f95a777d396ff7894a7a83dc9b0 < a1735eae55448bc79c2da6593455791e886f6ed8`\n- `Linux 2.6.30`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}